Die Top System (DTS®) – A competitive extension of mAgic sintering
Is automotive electrification shaping up to be the biggest undertaking of the Power Electronics industry? From observations, development activities for vehicle electrification have increased intensely and are very much thriving.
Power solutions for E-Mobility require miniaturization, energy efficiency and necessitate incredible reliability. Conventional power modules have little improvement head room to deliver the required performances. Wide band gap semiconductors are widely accepted to be the answer for efficiency improvement and to enable power density increase, i.e. miniaturization.
To operate reliably, new packaging material solutions are required to handle higher currents and increase in operating temperatures often associated with SiC-based semiconductors.
Die backside interconnections need to transfer thermal energy effectively away and be mechanically robust to secure the materials through extreme conditions. Heraeus Electronics mAgic sinter technology draws upon the mechanical pressure mechanism to form a densely packed joint layer, offering remarkably 4 times higher thermal conductivity than traditional solder to efficiently cool the overheating semiconductors.
Similar to die backside attachment, sintering also enables advanced frontside interconnections. The frontside sintering of either metal clips, flexible circuit boards or copper plates has been reported. Heraeus Electronics chose to develop the later solution to allow for the wedge bonding of copper wires or ribbons without breaking the die (Die Top System or DTS®).
To facilitate its implementation, DTS® is provided with pre-applied sinter paste. The fast placement on top of the die using a regular die bonder is ensured with a temporary B-stage fixation dot. Furthermore, the die and the DTS® can be sintered together in one row.
Due to the high tensile strength and the rather low CTE of the thin copper plate (50 µm), and the superior mechanical properties of the sinter layer, no wire lift off or cohesive break in the bonding layer are observed during power cycling. Instead, the failure mode proceeds from the propagation of cracks in the frontside metallization of the die.
To be able to use the full potential of the technologies mentioned, it is essential to ensure reliable front-side contact. These required and desired properties can ideally be achieved using copper bond wires and ribbons. Furthermore, ribbons can have advantages over wires in terms of productivity, which ultimately lead to improved output with the same machine park.
Our innovative product portfolio, our application knowhow and our expertise in matching materials are qualifying us to support you in a unique way. We do not only have the knowhow to integrate materials in a system, but also have a deep understanding of optimizing materials and material combinations and the possibility to test them under real conditions.